Devops Engineer

1. In contrast to the scripted pipeline, the declarative Jenkins pipeline doesn't permit a developer to inject code. A Groovy script or a Java API reference in a declarative pipeline will cause a compilation failure.

2. Declarative pipelines always begin with the word pipeline. Scripted pipelines, on the other hand, always begin with the word node. Declarative pipelines break down stages into individual stages that can contain multiple steps. Scripted pipelines use Groovy code and references to the Jenkins pipeline DSL within the stage elements without the need for steps.

Jenkins master will have the cron entries set up for the jobs as per the scheduled Job's configurations. As and when the time for a particular job comes, it commands agents (based on the configuration of the job) to execute the job with required configurations.

1. Purpose : 
Ansible : Configuration management, application deployment, and infrastructure automation 
Jenkins : Automation of Build and Release process and Orchestration of pipelines

2. Contributors :
Ansible : Redhat and the open-source community 
Jenkins : Cloudbees, Open Source Lab, CD.Foundation, Redhat, AWS, Github, Jfrog, the open-source community
 

3. UI Availability :
Ansible : Yes – Ansible tower is the UI dashboard for Ansible 
Jenkins : Yes – It is a web dashboard
 

4. Supported OS :
Ansible : Linux, macOS, and Windows. For Windows, Ansible integrates with Powershell and is a bit cumbersome to use 
Jenkins : Linux, Windows, and macOS
 

5. Built on :
Ansible : Python 
Jenkins : Java

A pod is the core building block for running applications in a Kubernetes cluster; a deployment is a management tool used to control the way pods behave.

Load balancer distributes the requests among multiple backend services (of same type) whereas ingress is more like an API gateway (reverse proxy) which routes the request to a specific backend service based on, for instance, the URL.

1. Amazon ECS is the AWS solution for managing containers at scale. It helps you speed up the process of building, deploying and migrating your containerized applications. Designed with simplicity in mind, Amazon ECS reduces the burden of setting up network, compute and security configurations, and managing scalability. For example, you don’t need to build a generalized abstraction if you need a load balancer—ECS seamlessly integrates features such as AWS Application Load Balancer (ALB) and Network Load Balancer (NLB).
Amazon EKS can handle the heavy lifting of building and running Kubernetes workloads at scale. Kubernetes is known for its vibrant community and ecosystem, open-source APIs and broad flexibility. With EKS, you can access the full power of Kubernetes features, while enjoying the convenience of a managed cloud service.

2. In terms of security, the difference between ECS and EKS is strictly operational—ECS has a deep integration with IAM while EKS requires add-ons to enable IAM functionality. Other options that enable similar functions in EKS, such as Kiam, have additional costs and add system complexity.

3. Amazon ECS is a proprietary technology by AWS. This means you will be locked into Amazon infrastructure and will not be able to move your clusters to another cloud provider or on-premises.
Amazon EKS is based on Kubernetes, so it has much better support for portability of workloads. You can run clusters in any other Kubernetes environment, whether on another cloud provider’s managed Kubernetes platform, a cloud-agnostic Kubernetes platform like Rancher, or plain self-managed Kubernetes.

4. Amazon ECS is not an open-source product, so it does not have a community as such. The product is supported by Amazon—see pricing for the available support plans.Amazon EKS is based on Kubernetes, so you have access to the Kubernetes community, including Github repos, Slack channels, events, documentation, training resources, and more.

1. One potential use case for docker in docker is for the CI pipeline, where you need to build and push docker images to a container registry after a successful code build.
2. Building Docker images with a VM is pretty straightforward. However, when you plan to use Jenkins Docker-based dynamic agents for your CI/CD pipelines, docker in docker comes as a must-have functionality.
3. Sandboxed environments.
4. For experimental purposes on your local development workstation.

1. Basic
Monolithic architecture is built as one large system and is usually one code-base
Microservices architecture is built as small independent module based on business functionality

2. Scale
Monolithic architecture is not easy to scale based on demand
Microservices architecture is easy to scale based on demand.

3. Database
Monolithic architecture has shared database
Each project and module has their own database in Microservices architecture.
 

4. Deployment
Large code base makes IDE slow and build time gets increase in Monolithic architecture.
Each project is independent and small in size. So overall build and development time gets decrease in Microservices architecture. 
 

5. Tightly Coupled and Loosely coupled
Monolithic architecture is extremely difficult to change technology or language or framework because everything is tightly coupled and depend on each other
Microservices architecture is easy to change technology or framework because every module and project is independent